I think anything w/4x4 5.8 auto is mainly what you should look for.and same year would be nice. The more similarities you can get, the better.These are pretty interchangable believe it or not. Maybe you could call a wrecking yard that could tell you what would interchange with it.Some of them out here are pretty good about that.

 

A friend of mine had a somewhat similar problem to yours. His problem was every time he closed his doors a wee bit hard you could hear the fuel pump kick in. He spent weeks and about $300 bucks trying to 'trace and replace' the problem. Then one day his Ignition switch on the column stopped working as it had fallen apart inside the cylinder. he bought a new cylinder and installed it and guess what...it took him about a month to realize it though...No more door/fuel pump issue. Myhaps this is the same problem you are having?

 

It seems to be doing it more today, its quite a bit cooler outside, what parts may be temperature sensitive?

 

Ignition cylnders workings are made of mostly white metal so they could be affected by temperature. Connections and wire can be affected by temperature as well id the have cracks in them. But it would have to be more than just a couple of degrees of change to make a noticeable difference.

 

A 91 will have 2 pumps, 1 in each tank and that is all. That is the way my '90 is.

As for the code:

Code 212-Loss of IDM input to PCM or SPOUT circuit grounded

It sounds to me that there is a problem with the computer getting the proper input from somewhere. The computer is probably cycling on/off/on/off and keeps resetting the fuel pump relay. I would look into this more.

I will bet a dollar to a nickel that it is NOT fuel related. This probably is not what you wanted to hear, but some wire tracing is in store. I bet you find a wire with the insulation rubbed off touching something metal.

 

I was curious what IDM was and found this in another thread. Thought it might help.

 

I don't know how I totally overlooked that code 212 but if you go there, book says either "open", " shorted" harness, bad module or bad processor. Not sure are about easy way to diagnose it further, my book wants to run tests thru breakout box.

 

If this was a wire shorting, wouldnt it also cause problems while running or driving?

The only time it throws the code is when the pump wont shut off, after the pump finally shuts off it runs great, its just waiting for the pump to shut off.

 

Maybe and maybe not. There are different things that happen in the start cycle versus the run cycle.

I think the breakout box that stepman referred to is just testing the truck with another brain. There is an electrical problem. It may be wiring and it may be the ICM.

 

I think what you are looking for is more of an "open". Maybe between the coil and the module. The pump is supposed to "time-out" unless it gets a signal from the module that the engine is running which I believe it (module) gets from the neg side of the coil.
I think I would look for a bad connector at coil or tfi or use Fords "wiggle test". Next time you get the pump running excessively,wiggle the wires at these points and see if you can get it to shut off. I'm thinking it will be a wire breaking from a connector or a connector that is spread open too far.
Don't you just love electrical troubles?

 

No, the breakout box (BOB) that I mentioned is what Ford uses to make diagnostic easier. It plugs into the harness at the computer and you can probe the wiring with the veh on off unplugged or whatever. It gives you a way to tap into the wires.

 

Or it could be corrosion in the wire, like a battery terminal will, and then it doesn't allow all the voltage to go through due to the increased resistance. I had problems with a car high revving intermittantly and my mechanic found 4 corroded connections. Cleaned them and all was good. That was on an Audi when I was just learning repairs and didn't want to mess it up.

Corrosion can do weird things.

 

20 degrees cooler out, and every time I key her up now the pump runs
damnit, maybe time to take her in

 

Do the wiggle test. Open the hood up and start wiggling connections around the distributor, etc. You might find the one that is giving you the problem.

 

okay, Ive wiggled the hell out of everything I can find
with no results.
Im gonna go out and do it all over again just to be sure
I didnt miss anything